﻿#region

using System;
using System.Collections.Generic;
using System.Linq.Expressions;
using System.Reflection;

#endregion

#region - Legal -

///<legal>
/// Copyright © 2011, Tateeda Media Network
/// All rights reserved. http://tateeda.com
///
/// Redistribution and use in source and binary forms, with or without
/// modification, are permitted provided that the following conditions
/// are met:
///
/// - Redistributions of source code must retain the above copyright
/// notice, this list of conditions and the following disclaimer.
///
/// - Neither the name of the Tateeda Media Network, nor the names of its
/// contributors may be used to endorse or promote products
/// derived from this software without specific prior written
/// permission.
///
/// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
/// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
/// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
/// FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
/// COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
/// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES INCLUDING,
/// BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
/// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
/// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
/// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
/// ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
/// POSSIBILITY OF SUCH DAMAGE.
///</legal>

#endregion - Legal -

namespace Tateeda.ClinicalStudy.Base.Modules.Rules.Mapping {

    public class PropertySpecifier<T> {
        private readonly Func<T, object> _getter;
        private readonly PropertyInfo _setHelper;
        private readonly Action<T, object> _setter;

        public PropertySpecifier(Expression<Func<T, object>> expression) {
            Expression = expression;
            _getter = expression.Compile();

            // ksa todo : DynamicMethod instead?
            _setHelper = (PropertyInfo)((MemberExpression)Expression.Body).Member;
            _setter = (o, v) => _setHelper.SetValue(o, v, null);
        }

        public Expression<Func<T, object>> Expression { get; private set; }

        public string PropertyName {
            get {
                var me = Expression.Body as MemberExpression;
                if (me == null) {
                    throw new InvalidOperationException(Expression + " is not a member expression");
                }
                return me.Member.Name;
            }
        }

        public static IEqualityComparer<PropertySpecifier<T>> Comparer {
            get { return new _Comparer(); }
        }

        public V GetValue<V>(T source) {
            return (V)_getter(source);
        }

        public object GetValue(T source) {
            return _getter(source);
        }

        public void SetValue(T source, object value) {
            _setter(source, value);
        }

        public override string ToString() {
            return PropertyName;
        }

        #region Nested type: _Comparer

        private class _Comparer : IEqualityComparer<PropertySpecifier<T>> {
            #region IEqualityComparer<PropertySpecifier<T>> Members

            public bool Equals(PropertySpecifier<T> x, PropertySpecifier<T> y) {
                return x.PropertyName.Equals(y.PropertyName);
            }

            public int GetHashCode(PropertySpecifier<T> obj) {
                return obj.PropertyName.GetHashCode();
            }

            #endregion
        }

        #endregion
    }
}